To simplify \(-\sqrt[3]{54}\), we can start by factoring 54 into its prime factors:
\[ 54 = 2 \times 27 = 2 \times 3^3. \]
Now, we can rewrite the cubic root:
\[ -\sqrt[3]{54} = -\sqrt[3]{2 \times 3^3}. \]
Using the property of cube roots, we can separate the factors:
\[ -\sqrt[3]{54} = -\sqrt[3]{2} \times \sqrt[3]{3^3}. \]
Since \(\sqrt[3]{3^3} = 3\), we have:
\[ -\sqrt[3]{54} = -\sqrt[3]{2} \times 3 = -3\sqrt[3]{2}. \]
Thus, the simplified form of \(-\sqrt[3]{54}\) is:
\[ -\sqrt[3]{54} = -3\sqrt[3]{2}. \]